LNG工厂能耗分析及节能措施探讨

Analysis on Energy Consumption and Energy Efficiency of LNG Plant

为节约能源消耗,对天然气液化装置能源消耗进行了分析,提出应从设计和管理两个环节制定节能措施。设计环节应重点考虑系统内余热的利用,包括再生气换热技术、蒸发天然气(BOG)换热、贫富胺换热等,减少工厂自耗天然气量;对再生气、BOG直接利用,减少增压电费投入;对于耗能大户冷剂压缩机,应尽可能贴近实际工况提供组分等参数,优化混合冷剂配方设计,采用先空冷后水冷的方式对冷剂进行冷却。日常运行管理中应加强分子筛脱水、循环水系统、BOG回收等过程节能,并提升装置运行平稳率,降低装置能耗。

In order to cut energy consumption,this paper analyzes the energy consumption of natural gas liquefaction plant,and points out that the energy-saving measures should be formulated from both design and management.The design should focus on the utilization of residual heat in the plant including regeneration gas heat transfer,BOG heat transfer,and lean/rich amine heat transfer to reduce the amount of natural gas consumed by the plant,and the direct use of regeneration gas and BOG to reduce the electric charge for pressurization.For the energyconsuming refrigerant compressors,the design should set the parameters as close as possible to the actual operating conditions,optimize the mixed refrigerant formula,and cool the refrigerant by air cooling before water cooling.In daily operation,the management should strengthen efforts to cut energy use in molecular sieve dehydration,circulating water system and BOG recovery,and improve the overall running stability and energy efficiency for the plant.